This invention relates generally to the field of training devices and in particular to training devices wherein simulated smoke is used for training realism. Even more particularly, the invention may be described as a smoke generator for use in training devices for such operations as simulating smoke from structural fires.
The use of simulated environments for training purposes has had an increase in recent years which may be proportionally linked to the increased cost of utilizing operational environments for training purposes. This is particularly true in the realm of fire fighter training, where the only operational equipment available for realistic training would be obsolete and unusable vehicles and structures. The use of such does not provide adequate control over the training environment as to allow the instructor to selectively stress aspects of the training; for example, re-ignition due to latent heat in an area after the fire is initially extinguished. To allow for controlled training exercises, reusable training devices or fire fighting simulators have been devised, such as: the Deep Fat Fryer Fire Fighter Simulator and Method of U.S. Pat. No. 4,299,579 to Swiatosz; the Fire Fighting Training Device and Method of U.S. Pat. No. 4,303,396 to Swiatosz; and the Navy's 19F1 series Fire Fighter Trainers. The current method for producing smoke for the 19F1 Fire Fighter Trainers utilizes a gas burner heat source for heating air to combine via nozzle injection with a smoke producing agent. The heat source supplies hot smoke to all locations in the trainer where smoke is to be simulated through heated pipes, which presents decomposition problems, hot pipe insulation problems, lack of adequate control at the egress point and the vaporization point, and a lack of remote control capabilities. Locating remote gas burners at the various locations would present additional plumbing problems, in effect requiring three fluid conduits to each location, and the burners would be subject to contamination by fire extinguishing agents directed thereupon by trainees.
In order to facilitate the production of smoke for training purposes, several smoke generators have been devised, including U.S. Pat. No. 4,326,119 to Swiatosz and U.S. Pat. No. 4,349,723 to Swiatosz, both of which heat the smoke producing agent and do not utilize heated air for vaporization. Likewise, U.S. Pat. Nos. 3,891,826 to Seuthe and 3,990,987 to Rogers, disclose smoke generators which directly heat the smoke producing agent via heat transfer from containment vessels heated by electrical current.
A venerable patent to Stephens, U.S. Pat. No. 2,066,703, discloses a pre-combustion atomization device to facilitate the burning of viscous hydrocarbon fuels, which is in some respects similar to the system currently in use and which correspondingly shares the disadvantages therewith, although it may be totally acceptable as a pre-combustion heater.
Each of the above devices are believed to be useful for their intended purpose; however, none are considered to provide an improved alternative to the currently employed system.
The instant invention, however, solves some of the problems faced by the previous art by virtue of its innovative approach, to wit: the smoke generator utilizes an electrically resistive heater tube in a coiled configuration to heat pressurized air as the air passes through the tubing. The temperature of the coil is controllable, as is the rate of flow of the air. The tubing is located at the point where the smoke is desired, and is connected to a vaporizing nozzle which also receives a liquid smoke producing agent. Both the smoke producing agent and the pressurized air are supplied by conduit from central sources, respectively, and are distributed at low temperature and controlled rates. The tubing, nozzle, temperature control apparatus, and connections to the conduits for air and smoke producing agents may be modular and may be replicated as disired at various locations in the trainer.
The present invention thus presents an advantage over the prior art that a volume of smoke may be simulated at various locations in a trainer without extensive use of heated ducting and its attendant insulation problems.
A further advantage of the present invention is the improved efficiency of the smoke producing agent utilization due to the absence of condensation in the ducting.
Yet another advantage is the ability to control the volume and density of the smoke at the individual modules from a central location.
These and other advantages, features and objects of the invention may be more readily understood by reference to the description of the preferred embodiment and to the accompanying drawings in which the same reference numeral designates the same component, throughout.